Simultaneous synthesis of β-Si3N4 nanofibers and pea-pods and hand-fan like Si2N2O nanostructures by the CVD method

• β-Si3N4 nanofibers and Si2N2O nanostructures were synthesized by CVD.
• Na2SiF6 is a solid precursor of the β-Si3N4 and Si2N2O nanostructures.
• β-Si3N4 and Si2N2O nanostructures were grown at 4 h and 1300 °C.

The aim of this work is to synthesize a net of interwoven β-Si3N4 nanofibers and intertwined pea-pods and hand-fan like Si2N2O nanostructures by the chemical vapor deposition (CVD) method at a relatively low temperature (1300 °C) and short times (up to 4 h). A solid precursor (Na2SiF6) was thermally decomposed at 400 °C into two new products: 2NaF and SiF4. Afterwards, the SiF4 reacts with a flow of N2 (9 cm3/min) with O2 traces at 10 mbar and 1300 °C producing a net of β-Si3N4 nanofibers with defined diameters (100–200 nm up to 3 h and 30–100 nm at 4 h) and intertwined pea-pods and hand-fan like Si2N2O micro and nanostructures on the back side of a particulate SiC preform.